libguestfs: mount local

New in libguestfs ≥ 1.17.22 is the ability to mount the guest filesystem on a local mountpoint. Well, you can already do that using guestmount, but the new thing is that you can do it from the API (from any language).

Here is an example using guestfish:

$ guestfish --ro -a /dev/vg_pin/F16x64 -i
 
Welcome to guestfish, the libguestfs filesystem interactive shell for
editing virtual machine filesystems.

Type: 'help' for help on commands
      'man' to read the manual
      'quit' to quit the shell

Operating system: Fedora release 16 (Verne)
/dev/vg_f16x64/lv_root mounted on /
/dev/vda2 mounted on /boot

><fs> ! mkdir /tmp/mnt # creates a local directory
><fs> mount-local /tmp/mnt readonly:true
><fs> mount-local-run
# the errors come from a GNOME daemon that
# looks at all new mountpoints
libguestfs: error: lstat: /.Trash: No such file or directory
libguestfs: error: lstat: /.Trash-500: No such file or directory

Over in another terminal, we can see the filesystem mounted on the local directory /tmp/mnt:

$ ls /tmp/mnt
bin   dev  home  lib64       media  opt   root  sbin     srv  tmp  var
boot  etc  lib   lost+found  mnt    proc  run   selinux  sys  usr
$ cat /tmp/mnt/etc/redhat-release
Fedora release 16 (Verne)

Unmounting the filesystem causes the guestfish mount-local-run command to return (since that command was actually serving the FUSE requests from the kernel).

$ fusermount -u /tmp/mnt

5 Comments

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5 responses to “libguestfs: mount local

  1. nice one. That will give good extra flexibility

  2. MeNok

    hello there,
    i just wonder what`s the difference between guestfs_mount and guestfs_mount_local. It seems to me the two just do the same stuff which is mounting the image on the local filesystem. Or is it not with the first one?

  3. L

    Hi Rich,
    Recently i deployed latest 1.17.40 on my rhel6.1.
    When i ran a tiny program which was to test the function guestfs_mount_local() or those similar functions that mounts locally, Error prompted—undefined symbol guest_mount_local !
    Why didn`t this undefined symbol error prompt when the program was first compiled,but when it was run?
    Then i gave guestfish mount local a try in the shell, and found that ok.I thought it could not be something wrong with the installation.And then wierd happened—i ran the previous test program again,and it did mount the vm image on the host local directory! I doubted whether this was repeatable so i ran it again,and oops,it failed with the same error “undefined symbol guestfs_mount_local”.
    Maybe you can help me out of this.
    Thanks
    L

    • rich

      Please ask on the mailing list, particularly including details of how you installed libguestfs 1.17.40 on RHEL 6.1.

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